Acute hypocalcaemia

Question 1

What are signs and symptoms of hypocalcaemia?

Answer 1

CATs go numb” - convulsions, arrhythmias, tetany, and numbness in the hands and feet and around the mouth.

SPASMODIC

Spasms (carpopedal spasm - Trousseau’s sign - on inflation of cuff and block brachial artery, wrist and fingers flex and draw together.)
Perioral paraethesiae
Anxious, irritable, irrational
Seizures
Muscle tone increase in smooth muscle - colic, wheeze, dysphagia
Orientation impaired (time, place, person) and confusion
Dermatitis
Impetigo herpetiformis (pustules in pregnancy)
Chvostek’s sign - neuromuscular excitability may cause faical muscles to twitch when tapping over facial nerve (parotid).
Cardiomyopathy - long QT on ECG

Question 2

What are causes of hypocalcaemia with raised phosphate?

Answer 2

CKD
Hypoparathyroidism (incl. thyroid or parathyroid surgery)
Pseudohypoparathyroidism
Acute rhabdomyolysis
Hypomagnesaemia

Question 3

What are causes of hypocalcaemia with normal or low phosphate?

Answer 3

Vitamin D deficiency
Osteomalacia (raised ALP)
Acute pancretitis
Over hydration
Respiratory alkalosis - ionised calcium is low due to high pH

Question 4

Why do you have to do a corrected calcium?

Answer 4

A significant portion of calcium is bound to albumin - any alteration in albumin level will affect measured level of calcium

Question 5

what is the management for hypocalcaemia?

Answer 5

IV calcium gluconate 10%
Or if severe, calcium chloride
ONLY if acute

Maintenance doses of valium and vitamin D to prevent further decline

Question 6

What investigations to determine cause?

Answer 6

Albumin adjusted serum calcium
serum PTH
Serum phosphate
Serum vitamin D
U&E for CKD
ABG